const hexcase = 0; /* hex output format. 0 - lowercase; 1 - uppercase */
const b64pad = ''; /* base-64 pad character. '=' for strict RFC compliance */
const chrsz = 8; /* bits per input character. 8 - ASCII; 16 - Unicode */

const b64_md5 = s => {
    return binl2b64(core_md5(str2binl(s), s.length * chrsz));
};

const core_md5 = (x, len) => {
    /* append padding */
    x[len >> 5] |= 0x80 << (len % 32);
    x[(((len + 64) >>> 9) << 4) + 14] = len;

    let a = 1732584193;
    let b = -271733879;
    let c = -1732584194;
    let d = 271733878;

    for (let i = 0; i < x.length; i+= 16) {
        const olda = a;
        const oldb = b;
        const oldc = c;
        const oldd = d;

        a = md5_ff(a, b, c, d, x[i + 0], 7, -680876936);
        d = md5_ff(d, a, b, c, x[i + 1], 12, -389564586);
        c = md5_ff(c, d, a, b, x[i + 2], 17, 606105819);
        b = md5_ff(b, c, d, a, x[i + 3], 22, -1044525330);
        a = md5_ff(a, b, c, d, x[i + 4], 7, -176418897);
        d = md5_ff(d, a, b, c, x[i + 5], 12, 1200080426);
        c = md5_ff(c, d, a, b, x[i + 6], 17, -1473231341);
        b = md5_ff(b, c, d, a, x[i + 7], 22, -45705983);
        a = md5_ff(a, b, c, d, x[i + 8], 7, 1770035416);
        d = md5_ff(d, a, b, c, x[i + 9], 12, -1958414417);
        c = md5_ff(c, d, a, b, x[i + 10], 17, -42063);
        b = md5_ff(b, c, d, a, x[i + 11], 22, -1990404162);
        a = md5_ff(a, b, c, d, x[i + 12], 7, 1804603682);
        d = md5_ff(d, a, b, c, x[i + 13], 12, -40341101);
        c = md5_ff(c, d, a, b, x[i + 14], 17, -1502002290);
        b = md5_ff(b, c, d, a, x[i + 15], 22, 1236535329);

        a = md5_gg(a, b, c, d, x[i + 1], 5, -165796510);
        d = md5_gg(d, a, b, c, x[i + 6], 9, -1069501632);
        c = md5_gg(c, d, a, b, x[i + 11], 14, 643717713);
        b = md5_gg(b, c, d, a, x[i + 0], 20, -373897302);
        a = md5_gg(a, b, c, d, x[i + 5], 5, -701558691);
        d = md5_gg(d, a, b, c, x[i + 10], 9, 38016083);
        c = md5_gg(c, d, a, b, x[i + 15], 14, -660478335);
        b = md5_gg(b, c, d, a, x[i + 4], 20, -405537848);
        a = md5_gg(a, b, c, d, x[i + 9], 5, 568446438);
        d = md5_gg(d, a, b, c, x[i + 14], 9, -1019803690);
        c = md5_gg(c, d, a, b, x[i + 3], 14, -187363961);
        b = md5_gg(b, c, d, a, x[i + 8], 20, 1163531501);
        a = md5_gg(a, b, c, d, x[i + 13], 5, -1444681467);
        d = md5_gg(d, a, b, c, x[i + 2], 9, -51403784);
        c = md5_gg(c, d, a, b, x[i + 7], 14, 1735328473);
        b = md5_gg(b, c, d, a, x[i + 12], 20, -1926607734);

        a = md5_hh(a, b, c, d, x[i + 5], 4, -378558);
        d = md5_hh(d, a, b, c, x[i + 8], 11, -2022574463);
        c = md5_hh(c, d, a, b, x[i + 11], 16, 1839030562);
        b = md5_hh(b, c, d, a, x[i + 14], 23, -35309556);
        a = md5_hh(a, b, c, d, x[i + 1], 4, -1530992060);
        d = md5_hh(d, a, b, c, x[i + 4], 11, 1272893353);
        c = md5_hh(c, d, a, b, x[i + 7], 16, -155497632);
        b = md5_hh(b, c, d, a, x[i + 10], 23, -1094730640);
        a = md5_hh(a, b, c, d, x[i + 13], 4, 681279174);
        d = md5_hh(d, a, b, c, x[i + 0], 11, -358537222);
        c = md5_hh(c, d, a, b, x[i + 3], 16, -722521979);
        b = md5_hh(b, c, d, a, x[i + 6], 23, 76029189);
        a = md5_hh(a, b, c, d, x[i + 9], 4, -640364487);
        d = md5_hh(d, a, b, c, x[i + 12], 11, -421815835);
        c = md5_hh(c, d, a, b, x[i + 15], 16, 530742520);
        b = md5_hh(b, c, d, a, x[i + 2], 23, -995338651);

        a = md5_ii(a, b, c, d, x[i + 0], 6, -198630844);
        d = md5_ii(d, a, b, c, x[i + 7], 10, 1126891415);
        c = md5_ii(c, d, a, b, x[i + 14], 15, -1416354905);
        b = md5_ii(b, c, d, a, x[i + 5], 21, -57434055);
        a = md5_ii(a, b, c, d, x[i + 12], 6, 1700485571);
        d = md5_ii(d, a, b, c, x[i + 3], 10, -1894986606);
        c = md5_ii(c, d, a, b, x[i + 10], 15, -1051523);
        b = md5_ii(b, c, d, a, x[i + 1], 21, -2054922799);
        a = md5_ii(a, b, c, d, x[i + 8], 6, 1873313359);
        d = md5_ii(d, a, b, c, x[i + 15], 10, -30611744);
        c = md5_ii(c, d, a, b, x[i + 6], 15, -1560198380);
        b = md5_ii(b, c, d, a, x[i + 13], 21, 1309151649);
        a = md5_ii(a, b, c, d, x[i + 4], 6, -145523070);
        d = md5_ii(d, a, b, c, x[i + 11], 10, -1120210379);
        c = md5_ii(c, d, a, b, x[i + 2], 15, 718787259);
        b = md5_ii(b, c, d, a, x[i + 9], 21, -343485551);

        a = safe_add(a, olda);
        b = safe_add(b, oldb);
        c = safe_add(c, oldc);
        d = safe_add(d, oldd);
    }
    return Array(a, b, c, d);
}

const md5_cmn = (q, a, b, x, s, t) => {
    return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b);
}

const md5_ff = (a, b, c, d, x, s, t) => {
    return md5_cmn((b & c) | (~b & d), a, b, x, s, t);
}

const md5_gg = (a, b, c, d, x, s, t) => {
    return md5_cmn((b & d) | (c & ~d), a, b, x, s, t);
}

const md5_hh = (a, b, c, d, x, s, t) => {
    return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}

const md5_ii = (a, b, c, d, x, s, t) => {
    return md5_cmn(c ^ (b | ~d), a, b, x, s, t);
}

const safe_add = (x, y) => {
    const lsw = (x & 0xffff) + (y & 0xffff);
    const msw = (x >> 16) + (y >> 16) + (lsw >> 16);
    return (msw << 16) | (lsw & 0xffff);
}

const bit_rol = (num, cnt) => {
    return (num << cnt) | (num >>> (32 - cnt));
}

const str2binl = (str: String): Array<any> => {
    const bin = Array();
    const mask = (1 << chrsz) - 1;
    for (let i = 0; i < str.length * chrsz; i += chrsz) {
        bin[i >> 5] |= (str.charCodeAt(i / chrsz) & mask) << (i % 32);
    }
    return bin;
}

const binl2b64 = (binarray): String => {
    const tab = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
    let str = '';
    for (let i = 0; i < binarray.length * 4; i += 3) {
        const tripconst = (((binarray[i >> 2] >> (8 * (i % 4))) & 0xff) << 16) |
                          (((binarray[(i + 1) >> 2] >> (8 * ((i + 1) % 4))) & 0xff) << 8) |
                          ((binarray[(i + 2) >> 2] >> (8 * ((i + 2) % 4))) & 0xff);
        for (let j = 0; j < 4; j++) {
            if (i * 8 + j * 6 > binarray.length * 32) {
                str += b64pad;
            } else {
                str += tab.charAt((tripconst >> (6 * (3 - j))) & 0x3f);
            }
        }
    }
    return str;
}

const str2Arr = (str : String) : Array<any> => {
    const bytes = [];
    for (let i = 0; i < str.length; i++) {
        bytes.push(str.charAt(i).charCodeAt(0));
    }
    return bytes;
}

const arr2Str = (bytes) : String => {
    let str = '';
    for (let i = 0; i < bytes.length; i++) {
        str += String.fromCharCode(bytes[i]);
    }
    return str;
}

const id2Url = (pic_str : String) : String => {
    pic_str += '';
    const magic = str2Arr('3go8&$8*3*3h0k(2)2');
    const songId = str2Arr(pic_str);
    for (let i = 0; i < songId.length; i++) {
        songId[i] = songId[i] ^ magic[i % magic.length];
    }
    const songIds = arr2Str(songId);
    let res = b64_md5(songIds);
    res = res.replace(/\//g, '_');
    res = res.replace(/\+/g, '-');
    res += '==';
    return 'http://p4.music.126.net/' + res + '/' + pic_str + '.jpg';
}

export { id2Url }
